Hundreds of businesses filled the building. Many expressed mixed emotions about what lies ahead as far policies under Trump.

"The reigning theme is uncertainty, okay, everybody's waiting to see what's going to happen with NAFTA , with immigration and so forth," said Sergio Ornelas, who oversees the event.

As Trump makes plans to re-negotiate the North American Free Trade Agreement (NAFTA) and makes other policy changes, many worry about the effects on workers both foreign and in the U.S.

Panelists featuring analysts addressed hundreds of businesses at the summit about that very issue.

"The guys against NAFTA are the ones talking and we need to get more pro-NAFTA people talking," Ornelas said. "We need people to understand how Mexico helps the competitiveness. Changes are already moving and that was reflected in the exchange rate in the peso versus dollar and the projects with pipeline."

But some who took part in the summit think some change might be a good thing.

"I think some of the loopholes in NAFTA could be plugged," said Alan Russell, CEO of TECMA. "With some of those loopholes plugged, I think it will enhance the opportunities of suppliers in the U.S. and Mexico to fill those voids, where they're compliant with the NAFTA provisions as was intended."

Some said the not knowing what looms ahead is worse than anything.

"In general, it's going to be a very bad year for Mexico because of the uncertainty, more so than the final result," Ornelas said.

Last month, Trump signed an executive order to withdraw from the Tran Pacific Partnership, or TPP.